1. Field of the Invention
The present invention relates to a process for preparing pharmaceutically and agriculturally useful optically active alpha-arylalkanoic acids, esters and pharmaceutically acceptable salts thereof. More specifically, it is concerned with a method of producing optically active intermediates which are useful in preparing the optically active alpha-arylalkanoic acids, esters and pharmaceutically acceptable salts referred to above.
1. State of the Art
Numerous alpha-arylalkanoic acids (i.e. 2-arylalkanoic acids have been described, developed and found to be useful as pharmaceutical and agricultural agents. Specific compounds have been described in U.S. Pat. Nos. 3,385,386; 3,600,437; 3,624,142; 3,755,427; 3,904,682; and 3,912,748. Process for manufacturing those types of compounds have been described previously in U.S. Pat. Nos. 4,135,051; 3,975,431; 3,658,863; 3,663,584; 3,658,858; 3,694,476; and 3,959,364. More recently, various processes have been described in U.K. Patent Publication No. 2,042,543, published Sept. 24, 1980 (corresponding to U.K. application No. 8005752, filed Feb. 20, 1980); in European Patent Publication No. 0034871, published Sept. 2, 1981 (corresponding to European patent Application No. 81200210.3, filed Feb. 23, 1981); and in Tetrahedron Letters, Vol. 22, No. 43, pp. 4305-4308 (1981).